Load box for storage tank containment

ABSTRACT

A load box for containing liquid spillage has a container; with an upper access opening with a cover, attachable to a wall of a containment structure containing a liquid storage tank. An input opening configured to receive a discharge end of a tank conduit, and an output opening is configured to receive a suction end of a transport conduit. The container encloses a releasable connection between the suction end of the transport conduit and the discharge end of the tank conduit. An overflow opening is located such that liquid rising in the container flows through the overflow opening before rising to a level where liquid flows through one of the input and output openings, and an overflow conduit attached to the overflow opening is configured such that when a liquid level in the container rises to the overflow opening, liquid flows through the overflow conduit into the structure interior.

This invention is in the field of liquid storage tanks and containment structures, and in particular a load box apparatus for containing liquid that might leak from connections made when removing liquids from storage tanks

BACKGROUND

Large liquid storage tanks are used in a variety of industries. For example in the petroleum industry, oil is pumped from underground reservoirs to the surface at oil well sites. The oil coming from the well site is commonly connected to a pipeline system and conveyed to a central storage location through the pipeline system. Where such a pipeline system is not available however, one or more large storage tanks are placed on the well site, and the oil is pumped into the tanks. Periodically a transport will connect a conduit to the tanks and pump the oil from the tanks and haul it away.

Where the stored liquid, such as oil, poses an environmental hazard, the storage tanks must be located inside a containment structure that is configured to contain any liquid that might be spilled from the tank. Such containment structures typically include walls supported upright on the ground and extending around the tank, and an impervious liner made from plastic or the like that covers the ground and extends generally to the top of the inside surface of the walls, thereby forming a container. A typical containment structure is disclosed for example in Canadian Patent Number 2,362,105 to Mackie. A plurality of wall panels are connected end-to-end with corners as required to form an enclosure and the liner is laid on the ground and up over the top of the wall panels. Braces extend from the ground to the top of the wall outside the wall. The storage tanks are placed on the liner inside the enclosure.

It is also known to provide a containment structure that has a floor and walls extending upward from and sealed to the floor to form a container, such as disclosed in United States Published Patent Application Number 20110067761 of King.

The area enclosed by the walls and the height of the walls of the containment structure are configured to provide sufficient volume to contain the required amount of liquid, which is usually regulated in the jurisdiction where it will be used, based on the number and capacity of the tanks being contained.

In a typical oil well site, a conduit extends along the ground from the tank to the wall and then typically a connection coupling is provided at the wall where transport conduits can be connected to the tanks to remove oil from the tanks. As transport conduits are being connected to one another for transferring oil from a storage tank to a truck or like transport vehicle, the oil can be spilled out of the ends of the conduits and deposited on the ground. In addition, leakage can occur from the connection while the oil is transferred therethrough.

However, this undesired spillage is prevented by spillage containers configured to enclose the connection and contain any oil spilled during connection or use. Such spillage containers are commonly called load boxes or load line boxes and examples of same are disclosed in U.S. Pat. Nos. 5,647,412 and 7,673,658 to Brewer, and 5,313,991 to Murray et al. These load boxes also commonly include a suction hose connected to the loading conduit and configured to suck out the contents of the load box into the loading conduit using the same pump suction that is used to draw oil out of the storage tank.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a load box apparatus for containing spillage from conduit connections at a storage tank containment site that overcomes problems in the prior art.

The present invention provides, in a first embodiment, a load box apparatus for containing liquid spillage. The apparatus comprises a container with an access opening in an upper portion thereof, and a cover movable from a closed position covering the access opening, to an open position. The container is adapted to be attached to a containment wall of a containment structure, the containment structure defining a substantially sealed structure interior containing a liquid storage tank. An input opening is defined in an upper portion of a wall of the container, the input opening configured to receive a discharge end of a tank conduit, and an output opening is defined in an upper portion of a second wall, the output opening configured to receive a suction end of a transport conduit. The container is configured to substantially enclose a releasable connection between the suction end of the transport conduit and the discharge end of the tank conduit. An overflow opening is defined in a wall of the container, the overflow opening located such that liquid rising in the container flows through the overflow opening before rising to a level where liquid flows through one of the input and output openings, and an overflow conduit is connected at an input end to the overflow opening and has an output end inside the structure interior, and is configured such that when a liquid level in the container rises to the overflow opening, liquid flows through the overflow conduit into the structure interior.

The present invention provides, in a second embodiment, a method of containing liquid spillage when removing liquid from a storage tank, wherein the storage tank is contained in the interior of a containment structure with a containment wall enclosing a substantially sealed structure interior. The method comprises mounting a container to the containment wall, and providing an access opening in an upper portion thereof, and a cover movable from a closed position covering the access opening, to an open position; providing an input opening in an upper portion of a wall of the container, and inserting a discharge end of a tank conduit through the input opening into an interior of the container; providing an output opening in an upper portion of a second wall, and inserting a suction end of a transport conduit through the output opening into the interior of the container; connecting the suction end of the transport conduit to the discharge end of the tank conduit inside the container interior; providing an overflow opening in a wall of the container, and locating the overflow opening such that liquid rising in the container flows through the overflow opening before rising to a level where liquid flows through one of the input and output openings; and providing an overflow conduit connected at an input end to the overflow opening and having an output end inside the structure interior, and configuring the overflow conduit such that when a liquid level in the container rises to the overflow opening, liquid flows through the overflow conduit into the structure interior.

The present invention therefore provides a load box apparatus that substantially prevents spilled liquid from the container from spilling from the container into the uncontained area outside the interior of a containment structure by directing rising liquid back into the interior of the containment structure. The apparatus is also securely attached to the wall of the containment structure, rather than, as commonly in the prior art, simply being attached, sometimes loosely, to a tank conduit that is fixed to the containment structure. Such prior art apparatuses were subject to rotating on the tank conduit and spilling contained liquid onto the ground outside the containment structure.

DESCRIPTION OF THE DRAWINGS

While the invention is claimed in the concluding portions hereof, preferred embodiments are provided in the accompanying detailed description which may be best understood in conjunction with the accompanying diagrams where like parts in each of the several diagrams are labeled with like numbers, and where:

FIG. 1 is a schematic perspective view of an embodiment of the apparatus of the present invention for containing liquid spillage;

FIG. 2 is schematic sectional view is a schematic side view of the embodiment of FIG. 1;

FIG. 3 is a schematic top view of a containment structure defining a substantially sealed structure interior containing two liquid storage tanks, with the embodiment of FIG. 1 mounted on a wall of the containment structure, and with a transport conduit connected to a transport vehicle;

FIG. 4 is a schematic side view of the containment structure with the embodiment of FIG. 1 mounted on a wall of the containment structure as shown in FIG. 3;

FIG. 5 is a schematic side view of an alternate embodiment of the apparatus of the present invention for containing liquid spillage, where the container is mounted on a lower portion of the wall of the containment structure;

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

FIGS. 1 and 2 schematically illustrate an embodiment of a load box apparatus 1 of the present invention for containing liquid spillage. The apparatus 1 comprises a container 3 with an access opening 5 in an upper portion thereof. A cover 7 is pivotally attached to the container 3 about a pivot axis PA and the cover 7 is movable, as illustrated in FIG. 1, from a raised open position to a closed position covering the access opening 5.

The container 3 is adapted to be attached to a containment wall 9 of a containment structure 11 that defines a substantially sealed structure interior 13 containing one or more liquid storage tanks 15, such as schematically illustrated in FIGS. 3 and 4. An input opening 17 in an upper portion of a wall of the container 3 is configured to receive a discharge end 19 of a tank conduit 21. In the illustrated apparatus 1, the input opening 17 is defined in a back wall 23 of the container, opposite the front wall 25, and an output opening 27 in an upper portion of the front wall 25 is configured to receive a suction end 29 of a transport conduit 31, such as would be connected to a pump on a transport vehicle 33.

In the illustrated apparatus 1, the access opening 5 extends downward along a front wall 25 of the container to also provide the output opening 27. When in the closed position, the cover 7 thus covers the output opening 27, somewhat similar to the spill container disclosed in U.S. Pat. No. 5,647,412 to Brewer, but providing improved access to make connections. Alternatively the apparatus could be configured like the spill containment apparatus of U.S. Pat. No. 5,313,991 to Murray et al., with separate top access and side output openings.

Also in the illustrated apparatus 1, the input opening 17 is provided by a coupler fitting 35 sealed to the back wall 23 of the container 3. The coupler fitting 35 is adapted at an exterior end thereof for attachment to the discharge end 19 of the tank conduit 21, and is adapted at an interior end thereof inside the container 3 for releasable attachment to the suction end 29 of the transport conduit 31. Other suitable opening configurations will occur to those skilled in the art as well.

The container 3 is configured to substantially enclose the releasable connection 35 between the suction end 27 of the transport conduit 29 and the discharge end 19 of the tank conduit 21 to suck the liquid out of the storage tanks 15 through the connection and into the transport vehicle 31. When making such connections it is difficult to avoid spilling at least some small quantity of liquid, and such spilled liquid 39 falls down into the container 3.

Commonly a suction conduit is provided from the releasable connection to the bottom of the container, with a valve operative to connect the suction conduit to the suction end of the transport conduit such that spilled liquid 39 can be sucked out of the bottom of the container. If the spilled liquid 39 is not removed, the liquid level LL in the container 3 rises, and can reach a level where same flows out one of the input or output openings 17, 27.

To avoid the possibility of spilled liquid 39 spilling in an uncontained area, the apparatus 1 of the present invention provides an overflow opening 41 in a wall of the container 3 that directs spilled liquid to the contained area inside the inside the structure interior 13. The overflow opening 41 is located such that liquid rising in the container 3 flows through the overflow opening 41 before rising to a level where liquid flows through one of the input and output openings 17, 27. In the illustrated apparatus 1, the overflow opening 41 is located below both the input and output openings 17, 27 however since the input opening is provided by the coupler fitting 35 sealed to the container wall, spillage would not occur at that point, and in any event the input opening 17 is higher than the bottom 27B of the output opening 27, and so spilled liquid 39 would of course flow out the output opening 27 before reaching the level of the input opening 17.

An overflow conduit 43 is connected at an input end to the overflow opening 41 and has an output end inside the structure interior 13. The overflow conduit is configured such that when a liquid level LL in the container rises to the overflow opening 41, as schematically illustrated in FIG. 2, spilled liquid 39 flows through the overflow conduit 43 into the structure interior 13. In the apparatus 1 of FIG. 2, the overflow conduit 43 can be very short as the interior 13 of the containment structure 11 is close to the overflow opening, however same can be configured as necessary to suit different applications.

In the apparatus 1 of FIGS. 1 and 2, the container 3 is adapted as schematically illustrated to be attached to the containment wall 9 such that the overflow opening 41 is above a top edge of the containment wall 9 such that the overflow conduit 41 passes over the conduit wall 9.

FIG. 5 schematically illustrates a different embodiment of the apparatus 101 of the present invention where the container 103 is adapted to be attached to the containment wall 9 such that the overflow opening 141 is below a top edge of the containment wall 9 and such that the overflow conduit 143 passes through a hole 147 in the containment wall 9, and is sealed to the hole 147 in the containment wall 9. A check valve 149 in the overflow conduit 143 prevents any contained liquid from flowing from inside the structure interior through the overflow opening 141.

The height of the walls 9 and their configuration define a volume of the structure interior 13 that is generally calculated so that the apparatus 1 can contain all the liquid that is stored in the tanks 15 that will be located in the apparatus 1. Thus the overflow opening 141 and input opening 117 must be sealed to the wall 9 and flow therethrough out of the structure interior prevented. The input opening 117 is sealed to the tank conduit 21 so leakage there is prevented, however a check valve 149 is provided in the overflow conduit 143 to prevent any contained liquid from flowing from inside the structure interior through the overflow opening 141.

FIG. 5 also schematically illustrates a secondary container 151 adapted to be located inside the structure interior 13. The output end of the overflow conduit 143 is configured to direct liquid into the secondary container 151, to avoid a mess.

The invention also provides a method of containing liquid spillage when removing liquid from a storage tank 15, wherein the storage tank 15 is contained in the interior of a containment structure 11 with a containment wall 9 enclosing a substantially sealed structure interior 13. The method comprises mounting a container 3 to the containment wall 9, and providing an access opening 5 in an upper portion thereof, and a cover 7 movable from a closed position covering the access opening, to an open position; providing an input opening 17 in an upper portion of a wall of the container 3, and inserting a discharge end 19 of a tank conduit 21 through the input opening into an interior of the container 3; providing an output opening 27 in an upper portion of a second wall of the container 3, and inserting a suction end 29 of a transport conduit 33 through the output opening 27 into the interior of the container 3; connecting the suction end 29 of the transport conduit 31 to the discharge end 19 of the tank conduit 21 inside the container interior; providing an overflow opening 41 in a wall of the container 3, and locating the overflow opening 3 such that liquid 39 rising in the container 3 flows through the overflow opening 41 before rising to a level where liquid 39 flows through one of the input and output openings 17, 27; and providing an overflow conduit 43 connected at an input end to the overflow opening 41 and having an output end inside the structure interior 13, and configuring the overflow conduit 43 such that when a liquid level LL in the container rises to the overflow 13.

The present invention therefore provides a load box apparatus 1 that substantially prevents spilled liquid from the container 3 from spilling from the container 3 into the uncontained area outside the interior 13 of a containment structure. Liquid rising in the container 3 of the apparatus 1 flows through the overflow opening 41 and overflow conduit 43 back into the interior 13 of the containment structure before it can flow out the output opening 27 on to the ground outside. The apparatus 1 is also attached to the wall 9 of the containment structure 11. Prior art spill containment apparatuses were commonly attached to a tank conduit 21 fixed to the containment structure and were subject to rotating on the tank conduit 21, such that liquid inside would spill onto the ground outside the containment structure.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in structure or operation which may be resorted to are intended to fall within the scope of the claimed invention. 

What is claimed is:
 1. A load box apparatus for containing liquid spillage, the apparatus comprising: a container with an access opening in an upper portion thereof, and a cover movable from a closed position covering the access opening, to an open position; the container adapted to be attached to a containment wall of a containment structure, the containment structure defining a substantially sealed structure interior containing a liquid storage tank; an input opening in an upper portion of a wall of the container, the input opening configured to receive a discharge end of a tank conduit; an output opening in an upper portion of a second wall, the output opening configured to receive a suction end of a transport conduit; wherein the container is configured to substantially enclose a releasable connection between the suction end of the transport conduit and the discharge end of the tank conduit; an overflow opening in a wall of the container, the overflow opening located such that liquid rising in the container flows through the overflow opening before rising to a level where liquid flows through one of the input and output openings; and an overflow conduit connected at an input end to the overflow opening and having an output end inside the structure interior, and configured such that when a liquid level in the container rises to the overflow opening, liquid flows through the overflow conduit into the structure interior.
 2. The apparatus of claim 1 wherein the overflow opening is located below the input and output openings.
 3. The apparatus of claim 1 wherein the container is adapted to be attached to the containment wall such that the overflow opening is above a top edge of the containment wall, and such that the overflow conduit passes over the conduit wall.
 4. The apparatus of claim 1 wherein the container is adapted to be attached to the containment wall such that the overflow opening is below a top edge of the containment wall, and such that the overflow conduit passes through a hole in the containment wall.
 5. The apparatus of claim 4 wherein the overflow conduit is sealed to the hole in the containment wall.
 6. The apparatus of claim 5 further comprising a check valve in the overflow conduit operative to prevent a flow of liquid from the structure interior to the overflow opening.
 7. The apparatus of claim 1 wherein the access opening extends downward along a front wall of the container to provide the output opening.
 8. The apparatus of claim 7 wherein the input opening is defined in a back wall of the container, opposite the front wall.
 9. The apparatus of claim 1 wherein the input opening is provided by a coupler fitting sealed to a wall of the container, the coupler fitting adapted at an exterior end thereof for attachment to the discharge end of the tank conduit, and adapted at an interior end thereof inside the container for releasable attachment to the suction end of the transport conduit.
 10. The apparatus of claim 1 further comprising a secondary container adapted to be located inside the structure interior, and wherein the output end of the overflow conduit is configured to direct liquid into the secondary container.
 11. A method of containing liquid spillage when removing liquid from a storage tank, wherein the storage tank is contained in the interior of a containment structure with a containment wall enclosing a substantially sealed structure interior, the method comprising: mounting a container to the containment wall, and providing an access opening in an upper portion thereof, and a cover movable from a closed position covering the access opening, to an open position; providing an input opening in an upper portion of a wall of the container, and inserting a discharge end of a tank conduit through the input opening into an interior of the container; providing an output opening in an upper portion of a second wall, and inserting a suction end of a transport conduit through the output opening into the interior of the container; connecting the suction end of the transport conduit to the discharge end of the tank conduit inside the container interior; providing an overflow opening in a wall of the container, and locating the overflow opening such that liquid rising in the container flows through the overflow opening before rising to a level where liquid flows through one of the input and output openings; and providing an overflow conduit connected at an input end to the overflow opening and having an output end inside the structure interior, and configuring the overflow conduit such that when a liquid level in the container rises to the overflow opening, liquid flows through the overflow conduit into the structure interior.
 12. The method of claim 11 wherein at least one of the input opening and output opening is configured such that liquid rising to a level of the at least one of the input opening and output opening will flow out of the container through the at least one of the input opening and output opening, and wherein the overflow opening is located below the at least one of the input opening and output opening. 